VIRUS = RANDOM REDIRECTIONS TO ENCODED URLS

Hello, I have my domain that is INFECTED. My domain hosts TWO PHP scripts one old (older php version) and one new (latest php version). My site is hosted on dedicated Linux server. The Virus redirects to RANDOM encoded URLS such as ONCE EVERY 24 hours. The virus uses cookie probably to show his URLS once every 24 hours: Sample of URLS 1) [login to view URL] 2) [login to view URL] 3) [login to view URL] KASPERSKY on my computer reports all those URLS as infected. The Virus replaces the URL in the browser bar of the browser with one of the encoded URLS listed above. The redirections happens even it's a basic .HTM file that is executed in internet browser (Firefox, Chrome, ANY). My dedicated server uses PHP 5.0 or lower because of one of PHP scripts is 10 years old so there may be vulnerabilities. MY personal computer is NOT infected and other people were able to replicate this issue on their computers when they visit my website. Please BID ONLY if you have experience in cleaning PHP scripts or dedicated servers and if you have dealt with similar cases. I don't have time to lose so beginners please do NOT bid. Payment will be sent by MILESTONE and requested BACK if you fail to find and clean my site. IMPORTANT: You are not allowed to make any major change on my server such as REINSTALLING APACHE, PHP etc without asking my permission. I will send you the root password once you are chosen and you can inspect and ask questions. Thanks!